I think you can delete all but the last restore point, by using disk cleanup (in the start menu) Look under the "more options" tab in the utility.
Otherwise, iof you want to really purge the folder, you will have to "take ownership" of the folder and files. You can do this manually, or just use the reg program attached. Just double click the.reg and it will give you a right click option on any files or folders where you wish to take ownership.